Patent GB-424283-A (GB)
Title: Improvements in or relating to soap manufacture
IPC: C11D9/26
Filed: 1933-08-18
Abstract: Fatty alcohols having 8--20 C. atoms are obtained by catalytic hydrogenation of fatty or naphthenic acids or their derivatives, e.g. esters, amides, chlorides.  Hardening of the fats by catalytic hydrogenation may be effected simultaneously.  Alcohols specified are octyl, nonyl, decyl, undecyl, lauryl, tridecyl, myristyl, pentadecyl, palmityl, margaryl, linoleyl, oleyi, hypogael, ricinoleyl, stearyl, and nonadecyl.  Catalysts specified are zinc, copper, cobalt, nickel, platinum, chromites, and copper oxide with chromium oxide, zinc oxide, or manganese oxide. Suitable temperatures are 200--450 DEG C.; suitable pressures over 10 atmospheres.  In examples: (1) a mixture of palm kernel oil, cottonseed oil, and tallow is passed continuously at 385 DEG  C. and 200 lb. pressure with excess hydrogen over a catalytic mixture of zinc chromite and copper chromite.  (2) Castor oil is passed with hydrogen at 390 DEG  C. and 2700 lb. pressure over a catalytic mixture of chromites of zinc, copper, and cadmium; it is then hardened by treatment with hydrogen at 150 DEG C. and 150 lb. pressure in presence of nickel.ALSO:Soap is superfatted without risk of rancidity by adding one or more fatty alcohols having 8--20 carbon atoms and obtained by catalytic hydrogenation of fatty acids (including naphthenic acids) or their derivatives, e.g. esters, amides, chlorides.  The alcohols may be added to the semifinished or stock soap, or to the fatty acids, fats or oils prior to saponification with alkali. Conveniently a part of the soap fat is converted into alcohols by hydrogenation and added to the remaining fat to be saponified; or the entire soap stock fat may be mildly hydrogenated to convert a part of the glycerides to alcohols; or the required concentration of alcohols may be obtained simultaneously with hardening of the fats by catalytic hydrogenation. The saponification may be effected by cold, boiling, or semi-boiling processes.  Alcohols specified are octyl, nonyl, decyl, undecyl, lauryl, tridecyl, myristyl, pentadecyl, palmityl, margaryl, linoleyl, oleyl, hypogael, ricinoleyl, stearyl, and nonadecyl.  Other substances may also be added, e.g. hydrocarbons, hydrogenated phenols, paraffin or other waxes, resins, starch, naphthalene, drugs, perfumes.  Catalysts specified are zinc, copper, cobalt, nickel, platinum, chromites, and copper oxide with chromium oxide, zinc oxide, or manganese oxide.  Suitable temperatures are 200--450 DEG C.; suitable pressure, over 10 atmospheres.  In examples: (1) 900 lb. of palm-kernel oil, 600 lb. of cottonseed oil, and 400 lb. of tallow are mixed; 200 lb. of the mixture is withdrawn and passed continuously at 385 DEG  C. and 2000 lb. pressure with excess hydrogen over a catalytic mixture of zinc chromite and copper chromite; about 85 per cent of the fats is converted to alcohols. The hydrogenated and non-hydrogenated fats are mixed and then boiled with 1555 lb. of 30 DEG  B<\>ae soda lye, and finished with 100 lb. of fresh palm-kernel oil.  (2) Castor oil is passed with hydrogen at 390 DEG  C. and 2700 lb. pressure over a catalytic mixture of chromites of zinc, copper, and cadmium, thus decreasing the saponification value about 60 per cent and reducing the iodine No. from 85 to 55.  The still fluid product is then treated with hydrogen at 150 DEG  C. and 150 lb. pressure in presence of nickel to saturate olefinic groups.  The white solid fragrant product, containing octadecanediol, stearyl, heptyl, undecyl, and other alcohols, synthetic wax, and hardened castor oil, is saponified with the theoretical amount of caustic soda.  This soap may be used to superfat other soaps; thus 10--15 per cent may be added to white toilet soap.